A typical circuit board system comprises a circuit board furnished with electrical components. The circuit board comprises a body made of one or more layers of electrically insulating material and electrical conductors on one or both of the surfaces of the circuit board and/or between the layers of the electrically insulating material. Each of the electrical components can be, for example, an integrated circuit such as a processor or a memory, or a discrete component such as a resistor, a capacitor, an inductor, a transistor, or a diode. Furthermore, the circuit board system may comprise also other elements than electrical components. Examples of the other elements are mechanical support elements and elements related to cooling arrangements.
A cooling arrangement is needed when heat generation of an electrical component is so high with respect to the mechanical dimensions of the electrical component that the ability of the outer surface of the electrical component to transfer heat to ambient air is not sufficient. For the sake of illustration, we consider a case where the circuit board system comprises an electrical component on one side of a circuit board. The cooling arrangement may comprise for example a cooling element installed on top of the electrical component. In some cases, it is however mechanically not possible to place the cooling element on top of the electrical component. In another example, the cooling arrangement comprises a heat conductive pathway for conducting heat generated by the electrical component through the circuit board to the other side of the circuit board and the cooling arrangement further comprises a cooling element on the other side of the circuit board so that the cooling element is in heat conducting relation with the heat conductive pathway. In some cases, it is however mechanically not possible to place the cooling element so that the cooling element is located on the opposite side of the circuit board with respect to the electrical component to be cooled.